Clip-on eyewear, in one form or another, has been in use for over fifty years. The most common use is for a primary eyeglass frame, usually holding prescription lenses, to support an auxiliary eyeglass partial frame, usually holding sunglass lenses. One or both of the primary and auxiliary frames would be manufactured with structure to enable the user to mount the auxiliary partial frame onto the primary frame, so that the auxiliary (sunglass) lenses would be positioned in front of the primary (prescription) lenses. Many different configurations of clip-on eyewear have been designed. Clip-on sunglasses allow consumers to purchase a pair of sunglasses at an affordable price and enable prescription glasses to function as sunglasses by simply attaching the clip-on accessory.
Early embodiments of clip-on eyewear involving clip-on sunglasses were equipped with metal hooks or clamping mechanisms for attaching to prescription glasses. In order to attach the clip-on sunglasses to the prescription glasses, the clip-on was twisted and the metal hooks were affixed over the eyerim of the prescription glasses.
U.S. Pat. No. 569,117 issued to Mosher discloses a non-magnetic clip-on for attaching to a primary frame. However, the clips of the Mosher invention are constructed of metal. Further, the auxiliary clip-on of Mosher's invention employs a yielding ligament between the two lenses. And finally, the auxiliary clip-on of Mosher's invention is meant to put on or taken off while the primary frame is being worn.
A later embodiment of clip-on eyewear employed magnets to attach an auxiliary frame to a primary frame. By replacing the hooks with magnets, the clip-on sunglasses attached without twisting and hooking the clip-on. The magnets can be placed in a variety of positions. The initial magnetic embodiment involved front-mounted magnets. U.S. Pat. No. 5,416,537 issued to Sadler discloses a front-mounted magnetic eyewear invention. The subsequent magnetic embodiments moved the magnets to a variety of other locations such as top-mounted magnets, bridge-mounted magnets, back-mounted magnets, and bottom-mounted magnets.
U.S. Pat. No. 5,568,207 issued to Chao (reissued as Pat. No. RE37,545 E) discloses auxiliary lenses that magnetically engage with the primary eyeglass frame. In this disclosure, the configuration of the primary eyeglass frame and auxiliary lenses only prevent downward disengagement of the auxiliary lenses.
U.S. Pat. No. 6,116,730 issued to Kwok is an improvement on previous magnetic eyewear patents, such as U.S. Pat. No. 5,568,207 issued to Chao. In Kwok, the auxiliary lens frame securely attaches to the primary eyeglass frame whereby disengagement of the auxiliary lens frame from the primary eyeglass frame is prevented in all directions. The auxiliary lens frame is manufactured with engaging magnets contained on two sides projection members thereof in protective mounting collars, each having flanges that prevent the auxiliary lenses and primary eyeglass frame from becoming disengaged due to movement of the wearer when engaged.
This magnetic clip-on eyewear met the needs of consumers who had become more athletic and design-aesthetic conscious. The consumer's requirements for clip-on eyewear became more exacting as to the need for secure mounting and position-holding of the two assemblies, as well as the attractive appearance, using light weight metals with thin profiles.
However, despite their advantages over the metal hook variety, the magnetic attaching sunglasses had certain flaws as well. First, there are concerns regarding a pair of magnets emitting electromagnetic radiation on each side of the head for prolonged periods of time. There is no research yet that proves that this proximity for long durations of time is harmless. Second, there is the possibility of increased risk due to electromagnetic radiation directly next to cellular telephones. Third, there is the possibility that the magnets may be harmful to the cell phones. The impacts of magnets are still the subject of many studies.
Electromagnetic radiation cannot be shielded completely. Children are more vulnerable than adults to electromagnetic radiation. Cell phones have been linked to cancer. Electromagnetic radiation depletes lymphocytes that are part of the immune system. Power line electromagnetic radiation has been proven to cause leukemia. To date, exactly how much exposure to electromagnetic radiation can be harmful to health remains an unsolved scientific and medical issue.
Further, there is the possibility of issues associated with the magnets themselves. The magnets may fall out of the eyewear. The magnets may corrode. The magnets may corrode inherently; however, the movement of the magnets in some inventions may cause increased wear. For example, U.S. Pat. No. 5,568,207 issued to Chao only restricts downward disengagement versus U.S. Pat. No. 6,116,730 issued to Kwok which further restricts movement due to the presence of flanges on the auxiliary lens frame. In addition, when the magnets of the clip-on or frame are in a bag, such as a purse, stray objects such as paper clips are attracted to the eyewear. These situations cause either inconvenience, damaging scratches to lenses, and/or cost to consumers.
In addition, prior art clip-on eyewear is capable of one handed mounting and removal of the auxiliary assembly to and from the primary assembly, when the primary assembly is being worn but such action causes that one hand to be put in front of one's eyes, often when driving a car or descending stairs—which poses a safety problem.
U.S. Pat. No. 5,608,470 issued to Sheffield discloses a prescription lens attachable to safety glasses. The safety glasses are equipped with a projecting rim. The prescription lens is constructed with a sloping edge to fit into the projecting rim of the safety glasses. The prescription lens fits in the inside of the safety glasses between the wearer's face and the safety glasses. This invention is quite different from other clip-on eyewear inventions due to the fact that attachment occurs on the inside of the primary frame rather than the outside. A distinct disadvantage of this invention is that both the safety glasses and the prescription lenses must be specially constructed with either a projecting rim or the appropriate sloping edge in order for engagement to occur.
U.S. Pat. No. 6,113,234 issued to Huang discloses a non-magnetic clip-on for attaching to a primary frame. In Huang, both the primary frame and the auxiliary frame require special modification to effectuate engagement. The primary frame is constructed with recessed notches, while the auxiliary frame is constructed with hooks. The alignment of the hooks and notches is critical to engagement.
U.S. Pat. No. 6,234,627 issued to Agnoli also discloses a non-magnetic clip-on eyewear invention. Specifically, Agnoli discloses an eyeglass device with a removable supplemental lens. In Agnoli, the primary frame must be manufactured with tabbed projections to meet with the notches of the auxiliary frame in order for attachment to occur.
U.S. Pat. No. 6,244,705 issued to Ledbetter discloses auxiliary corrective eyeglasses for use with primary eyeglasses. In Ledbetter, there is no clipping, attachment, or engagement involved. In Ledbetter, the auxiliary frame merely rests on the inside of the primary frame. There are clear disadvantages to this invention that fails to provide a secure means for maintaining the auxiliary frame in its proper, desired position.
U.S. Pat. No. 6,260,964 issued to Kroman discloses a non-magnetic clip-on eyewear invention. The auxiliary frame in Kroman slides into position in front of the primary frame. Both the primary frame and auxiliary frame must be constructed with curved portions for attachment to occur.
Utility Pat. No. RE37,523 issued to Bondet discloses eyeglasses having interchangeable lenses and attachment clips in contrast to clip-on eyewear which involves a separate auxiliary and primary frame. There are many disadvantages associated with this type of invention including but not limited to ease of use.
U.S. Pat. No. 6,354,703 issued to Sadler discloses a magnetic clip-on eyewear invention. In particular, Sadler discloses eyeglass devices having auxiliary eyeglasses with magnetic clamp mounting. The numerous potential disadvantages associated with magnetic clip-on eyewear have been discussed above. There are further disadvantages associated with the Sadler invention due to the fact that the magnetic features of the invention are a separate entity from the auxiliary and primary frames and thus could become more easily lost or damaged.
U.S. Pat. No. 6,364,478 issued to Jagasia discloses an eyeglass device having primary and auxiliary frames with lenses and method for forming the same. As Jagasia is a clip-on magnetic eyewear invention, it too is subject to the numerous potential disadvantages associated with magnetic clip-on eyewear discussed above.
U.S. Pat. No. 6,550,912 issued to Vitaloni discloses spectacles with additional removable lens or lenses. This non-magnetic clip-on eyewear invention requires that the primary frame be manufactured with means for clasping the auxiliary lenses.
For these reasons, a biologically safe clip-on is needed which attaches with neither metal hooks nor magnets.